Shock absorber



July 23, 1931. H. A. Tum.; .1,816,029-

' sHocK ABsoRBER Filed oct. 5. 192sl the brake shoe apart and thus forcethe shoe into increased frictional engagement withv the brake drum andalso to rotatepthe brake shoe in its frictional engagement with thedrums To this end, an operating shaft 44 is rotatably received in theapertures 22 and 16 respectively of the cover plate 18 and rear wall l2of the drum. An operating lever 46 is fixed tothe outer end of saidYshaft by any suitable means as fthe bolt 48 which passes through saidlever and a slot in the periphery of said shaft and outstands beyond theheads of the supporting bolts 24" so that it is free to oscillate inwhatever angular' position it may be located with respect to the brakedrum. The outer end of said lever isl connected by a universal joint 50of any, suitable construction to one end of a link 52 and the other endyof the link is suitably connected to a spring, or other part, notshown,

the movements of which are tobe controlled by the shock absorber.v I

The shaft 44 preferably is integral with a radially extended arm 54which is located within the Vdrum 10 and also within the brake shoe 30vand is constrained to reciprocate with said shaft. A cam finger 56overlies the opposite faces of said arm`54 and is pivoted thereto by apin 58 that passes through said finger and also through said arm. Theouter end 60 of said cam finger is located between theV confronting ends32 and 34 ofthe brake shoe and has flat parallel opposed faces whichclosely overlie the similar faces of the ends of Ythe brake shoe. Thecam finger prefer*- ably is made of hardened steel and the ends off thebrake shoeare provided with removable hardened steel wear-plates 62which are adapted to be engaged by said cam finger.

Said wear-plates have removable dove-tailed connections 63 with the endsof the brake shoe as illustrated in Fig. 5. When the brake shoe is in anormal position corresponding with the normal position ofthe automobilespring, the confronting ends of the wear-'plates are adapted to be closeto or in engagement with the opposite faces of the cam'finger and thecam finger is adapted to be radially disposedas illus-I trated in Fig.4. yWhen the shaft 44 is rotated in either direc-Y tion due to theaction of the springvvith which it is connected, the inner or pivotedend of the cam finger is moved out of its radial position into someinclined position with respect to the free ends ofthe brake shoes asillustrated in Fig. 6. In this plosition, one face of theV cam fingerpresses against an inner portion ofthe face Vof one end ofthe brake shoeand against an outer portion of the face of the other end of the brakeshoe'thereby forcing the ends ofthe shoe apart and Vconsequentlyforcing. the brake shoe into increased frictional engagement with thestationary drum. At the same time, the rotation of the shaft causes thebrake shoe to be rotated within the drum. Consequently, the brake shoeopposes the rotation of the shaft and thus the action ofthe spring.

' Vhen the spring moves in the opposite direction, as on the rebound,the shaft 44 moves in the. opposite directionand thus restores the camfinger momentarily toits radial position, thus permitting the spring acertain amount of free movement at the start of its movement in suchdirection. Upon further movement, however, the cam finger is tilted inthe opposite direction from that shown in Fig. 6 vand so exerts abraking effect on the spring to retard its free movementin Vthisdirection. Consequently undue movement of the spring in both directionsis restricted while permitting a certain and desirable amount of freemovement of the spring. The

braking effect is also increased forsudden spring movements since themore suddenly bronze as the combination of bronze and cast iron frictionfaces has been found to be particularly effective and Wear-resistant.

Thecasing is adapted to be filled' withoilV to lubricate the brake facesand other partsof the mechanism that need lubrication.

I claim :V

l. A shock absorber having 'a stationary brake drum, aninternally-expanding brake shoe having confronting ends'and locatedinternally of and cooperating with said drum, and a reciprocableoperating member, the movements ofy which are to be controlled,liavingfan operativevconnection with said shoe between said confrontingends/'and which is arranged by its movement to expandV said shoe intofrictional engagement with said drum andy also to rotate said shoe. Y

2. A shock labsorber having a stationary brake' drum, 'a rotatableinternally-expanding brake 'shoe cooperatingwith said drum and havingconfronting ends, and an actuating member having a connection with saidbrake 'shoe between said ends by which movements of said member vareretarded,- said connection Ialso constituting means operated by itsrotation to expand said` brake shoe into engagement with said `drum andto rotate the expanded shoe. V Y

3. A shock absorber having a stationary brake drum, aninternally-expanding rotatable brake shoe cooperating Withsaid drum andhaving confronting ends, and a' I' 'l `said brake shoe by which torotate it, said connection'also constituting means operated by itsbrake-actuating movements to force the confronting ends of said brakeshoe apart and the shoe into frictional engagement with said brake drum,said confronting means being disposed at least in part Ybetween saidconfronting ends.

5. A shock absorber having a stationary7 brake drum, a rotatable brakeshoelocated within said brake drum in frictional engagement therewithand having confronting ends, and a reciprocable actuating member havingmeans located between said confrontying ends `of said brake shoe andoperated byy reciprocatory movements thereof to force said ends apartand the brake shoe into increased frictional engagement with said drum,said means also constituting means to rotate said brake shoe.

6. A shock absorber having a stationary ybrake drum, a rotatable brakeshoe disposed internally of said drum in frictional engagement therewithand having confronting freeends, a shoe operating member located betweensaid confronting ends of said shoe and arranged to be tilted to spreadsaid ends apart and the shoe into increased frictional engagement withsaid drum, and an actuating shaft having a pivotal connection with saidtilting member arranged to rotate and tilt said member and also torotate said brake shoe.

7. A shock absorber having a stationary brake drum, a brake shoe locatedwithin said brake drum in frictional engagement therewith and havingconfronting free ends, a cam member disposed between said free ends andadapted to bear upon both of said ends and to tilt and force them apart,and an actuating shaft having a connection with said cam, member fortilting it and also for rotating said brake shoe.

8. A shock absorber having a stationary brake drum, a brake shoe locatedinternally of said drum in frictional engagement therewithy and havingconfronting free ends, an actuating shaft located co-axially with saidbraledrum and shoe, a cam finger disposed between the confronting freeends of said ybrakey shoe and arranged to fulcrum about both confrontingends and to force said ends apart and the brake shoe into increasedfrictional engagement with said brake drum and &

also to rotate said shoe, and an arm rotatablev with said shaft having apivotal connectionl with said cam finger.Y l

' `9. A shock absorber having a stationaryk brake drum, a rotatablebrake shoe located within said drum, and having confrontingv freeendg-means carried by said brake shoe urging it into frictionalengagement with said drum, a cam member located between said'confronting free ends arranged to rOcl; upon both of said ends andforce said ends apart and the brake shoe into increased frictionalengagement with said brake drum, and an actuating shaft having aconnection with said cam member arranged to rock it and also to rotatesaid brake shoe.

10. yA shock absorber having a brake drum, a brake shoe located withinsaid drum having confronting free ends, said brake shoe having arecessedV inwardly-directed boss opposite said confronting free ends, aplunger located within the recess and bearing against said brake drum, aspring bearing upon said brake slice and also upon said plunger wherebyto force said brake shoe into frictional en- Y gagement with said drum,a cam member located between said confronting free ends of said brakeshoe arranged to rock upon both of said ends and force said ends apartand the brake shoe into increased frictional engagement with said brakedrum, and an actuating shaft having a connection with said cam memberarranged to rock it and also to rotate said brake shoe.

11. A shock absorber having the combination of an enclosing casinghaving a cylindrical wall constituting a brake drum and an end wallwhich forms a closure for one end of said casing, said casing being openat the other end, a cover plate forming a closure for the open end ofsaid casing, a rotatable internally-expanding brake shoe havingconfronting ends and located within said casing in frictional engagementwith said brake drum, and a shaft located partly within said casinghaving a connection with said brake shoe by which to rotate it and alsoby which to eX- pand it .into frictional engagement with said brakedrum, said connection comprising a tiltable cam member engaged by saidconfronting brake ends and having an eccentric pivotal connection withsaid shaft.

12. A shock absorber having the combination of a casing having acylindrical wall constituting a brake drum and an end wall constitutinga closure for one end of the casing, a removable cover plate providing aclosure for the open end of said casing, a rotatable brake slice locatedwithin said brake drum having confronting free ends, a tilting camfinger located between said confronting free ends of said brake shoearranged to tilt upon both of said free ends and force them apart andthe brake shoe into frictional engagement with said brake drum, anoperating `shaft journalled in said cover plate and end Wall (3o-axiallyWith'said brake drum and brake Shoe, and an arm rotatable With saidshaft having a pivotal conneotionvwith said sfcani member arrangedtotilt it andralso to J rotate said brake Shoe.

In testimony whereof, I have signedl my name to this specification.

HENRY A. TUTTLE.y

